TM 5-3810-306-20Electrical SwivelThe electrical swivel center or collector ring assembly is secured by setscrews to a center post which is bolted to the spoolof the air/transmission swivel. This allows the collector ring assembly to remain stationary with the chassis. The outerportion or brush assembly is spring mounted on two pins which are located on a mounting plate welded to theair/transmission swivel barrel. This allows the brush assembly to rotate with the superstructure. The springs on themounting plate pins allow the swivel to float and not bind when the superstructure rotates.Electrical power is transferred to and from the carrier and superstructure through the electrical swivel. The swivel has 42slip rings.SUPERSTRUCTUREDistribution Panel All electrical circuits are protected, and some controlled, from the printed circuit board (circuit breakers)located in the cab right side panel. The printed circuit board consists of a harness with four connectors, six relays, ninecircuit breakers, and a flasher. The relays are energized to close their contacts any time the ignition switch is in the ON orACC position.Instrument Panel The instrument panel is located in the cab section of the crane. It contains all of the controls andindicators that the operator will use during crane operation. Additional information on the instrument panel and its controlsand indicators can be found in the Operators Manual TM 5-3810-306-10.AlarmsThe backup alarm is located above the pintle hook on the carrier. It serves as a warning to personnel that the crane istraveling in reverse.Superstructure Lighting Two lights mounted in the cranes superstructure are the cab floodlight and boom floodlight. Thecab floodlight is located on the outside of the cab and is controlled by the operator by a swivel handle inside the cab. Theboom floodlight is mounted on the telescoping boom and is used to illuminate the work area and hook block during nightoperations.CARRIER FRAMESending Units and SwitchesThe electrical system provides electrical power to a variety of sending units and switches that monitor the systems in whichthey are installed. These sending units and switches transmit signals to indicators and warning lights in the operators cab,allowing the operator to monitor the system and warn him of impending problems.1-20